A common problem for owners of mobile phone devices is that sometimes the phone is temporary lost, e.g. the user forgot where he/she (or any of the other family member) last put the phone in a home environment. One frequently used method to find such lost mobile phone device is simply to make a call and “follow the ring tones.” If a phone is lost in a public environment (perhaps the owner knows or suspect that the mobile phone is stolen) there are methods to track and find such mobile phone devices, e.g. based on user installed security application.
One problem is that since mobile devices are usually battery powered, the above mentioned methods are applicable only as long as the phone is powered on. If the phone is switched off due to low battery, or if the phone is manually turned off by any reason, then the phone cannot easily be found.